Typical end closures for beer and beverage containers have an opening panel and an attached leverage tab for pushing the opening panel into the container to open the end. The container is typically a drawn and ironed metal can, usually constructed from a thin plate of aluminum or steel. End closures for such containers are also typically constructed from a cutedge of thin plate of aluminum, formed into a blank end, and manufactured into a finished end by a process often referred to as end conversion. These ends are formed in the process of first forming a cutedge of thin metal, forming a blank end from the cutedge, and converting the blank into an end closure which may be seamed onto a container.
These types of container ends have been used for many years, with almost all such ends in use today being the “ecology” or “stay-on-tab” (“SOT”) ends in which the tab remains attached to the end after a tear panel, including large-opening ends (“LOE”), is opened. The tear panel being a portion of the can end defined by a score length. The tear panel may be opened, that is the score may be severed, and the tear panel displaced at an angular orientation relative to the remaining portion of the can end. The tear panel remains hingeably connected to the remaining portion of the can end by a hinge segment, leaving an opening through which the user draws the contents of the container. In an LOE, the opening is at least 0.5 square inches in area.
Opening of the tear panel is operated by the tab which is attached to the can end by a rivet. The tab is attached to the can end such that a nose of the tab extends over a proximal portion of the tear panel. A lift end of the tab is located opposite the tab nose and provides access for a user to lift the lift end, such as with the user's finger, to force the nose against the proximal portion of the tear panel.
When the tab nose is forced against the tear panel, the score initially ruptures at a vent region of the score. This initial rupture of the score is primarily caused by the lifting force on the tab resulting in lifting of a central region of the can end, immediately adjacent the rivet. As the tab is lifted further, the score rupture propagates along the length of the score, eventually stopping at the hinge segment.
Tabs are often also used to convey information to users. This information may be in the form of promotional materials, logos, or the like. Methods such as printing, incising, laser ablation, stamping, etc. have been employed to provide information on the tabs. To date, none of these methods has been widely accepted.
Some publications dedicated to methods of conveying information to a user in conjunction with beverage containers include: U.S. Publication No. 2006/0151501 which discloses a protective sanitary film for coating a can lid; U.S. Pat. No. 1,257,710 which describes a crimped bottle cap; U.S. Pat. No. 4,380,129 which described information-bearing tabs; U.S. Pat. No. 1,878,541 which describes an impressed cap; U.S. Pat. No. 4,203,240 which describes placing indicia on a beverage container; U.S. Pat. No. 4,459,910 which describes an embossing machine having upper tooling including multiple embossing stamps and lower tooling including an anvil only; U.S. Pat. No. 4,557,505 which discloses tamper evident tape; U.S. Pat. No. 5,191,695 which discloses a token which is insertable into the finger hole of a tab, which token may be marked by molding, embossing, hot die stamping, or ink jet printing where embossing is used only when thickness of tab is so great that indicia will not show through; U.S. Pat. No. 5,316,166 which is similar to U.S. Pat. Nos. 5,191,695; 6,080,958, 6,433,302, 6,501,046, 6,706,995 and 6,498,318 which describe marking tabs with embossing via stamping or incising; U.S. Pat. No. 6,105,806 which is primarily dedicated to a laser etched image on a tab; U.S. Pat. No. 6,202,880 which discloses a second score having a shape and laser markings; U.S. Pat. No. 6,777,098 which discloses laser marking an anodized aluminum; and U.S. Pat. No. 6,868,627 which describes indicia on a tab which indicia may consist of a mark, shape, depression, cut, mold, impression.
Other publications which may be relevant to providing indicia on non-detachable tabs include AU-784218, DE-19701547, DE-29716186, EP-0923457, GB-2105257, JP-3146174, WO-00/03832, WO-01/68460, WO-98/10945, and WO-99/09853.
Co-pending and commonly assigned U.S. application Ser. No. 12/365,696 also describes methods of decorating and strengthening can end tabs.
The development of thermochromic materials, such as those discussed in U.S. Pat. No. 5,928,126, has opened up new possibilities for the conveyance of information and decorative capabilities of can makers. However, to become a marketing tool, the thermochromic materials must be deposited in several layers, typically 3 to 4. Unfortunately, adding 3 to 4 layers of decoration to a can body or can lids is impractical and not advantageous to can makers for manufacturing reasons. For instance, the decorative ink on a can body is typically 0.8 microns to 1.5 microns thick. Unfortunately, ink carrying thermochromic materials does not look acceptable until it is preferably 2.5 microns to 5 microns thick. Such thickness cannot be achieved on can bodies in a typical manufacturing process. Thus, can bodies having thermochromic material deposited thereon have yet to become commercially successful.
The present invention is provided to solve the problems discussed above and other problems, and to provide advantages and aspects not provided by prior can end tabs of this type. A full discussion of the features and advantages of the present invention is deferred to the following detailed description, which proceeds with reference to the accompanying drawings.